
Proteins tend not to move out of the membrane.
The protein doesn't leave the membrane as a result of the transmembrane helix being very hydrophobic. This hydrophobicity and the hydrophobicity of the lipid tails means that they self-associate. A better way of describing it is that they fiercely dissociate from the water. A molecular dynamics simulation showed that even in simulations the membrane will readily self-assemble as a result of the hydrophobicity.
This is achieved by a few properties of the TMH sequence. There is a large amount of hydrophobic residues like leucine. At either end of the helix are large aromatic residues called the aromatic belt. Further is the electrostatic satisfaction offered by Gunnar von Heijne's famous positive inside rule and the recently identified negative-outside rule present in helices with evolutionary pressure to optimise anchorage.

(Image source: Baker et al., 2017)
Cymer et al. published a study showing the free energies associated with each part of the transmembrane protein helix (figure below). The overall ΔG for a transmembrane helix in the membrane is ~-12kcal mol−1. This means that the association of the helix in the membrane is typically spontaneous.

(Image source: Cymer et al., 2015)

A:

No other answer has mentioned this so I created an account just to say this.
Some membrane proteins do not move. This is because they are fixed in that position in the membrane due to the cytoskeleton. Erythrocytes are a good example of this. 
The main protein that is immobilised in erythrocyte membrane is Band 4.1 protein, and its immobilised by Spectrin. 
Spectrin forms a tetramer(2 dimers together) that acts like a chain/rope connecting membrane proteins and locking them in place.  Spectrin connects to the Band 4.1 protein (also to actin, but less important).
Spectrin also binds to Band 3 protein (via ankyrin, just a protein that connects spectrin to band 3). Band 3 is an anion channel (for HCO3- and Cl-, which is important for red blood cells to function. you want these band 3 proteins to remain evenly spaced out, so they are fixed in the membrane to make sure)

It is important for some membrane proteins not to move. Otherwise the cell will lose its function in some cases(like intestinal epithelial cells), imagine if SGLUT-1 (glucose
Proteins tend not to move out of the membrane. 
 The protein doesn't leave the membrane as a result of the transmembrane coil being very hydrophobic. This hydrophobicity and the hydrophobicity of the lipid tail means that they self - companion. A full way of describing it is that they ferociously dissociate from the water. A molecular dynamics model showed that even in simulations the membrane will promptly self - assemble as a result of the hydrophobicity. 
 This is achieved by a few properties of the TMH sequence. There constitute a large amount of hydrophobic residues like leucine. At either end of the helix are bombastic aromatic residues called the aromatic belt. far is the electrostatic satisfaction offered by Gunnar von Heijne's famous positive inside convention and the recently identified negative - outside rule present in helices with evolutionary atmospheric pressure to optimise anchorage. 

 (Image source: Baker et al. , 2017) 
 Cymer et al. published a study showing the free energies associated with each part of the transmembrane protein helix (figure below). The overall ΔG for a transmembrane helix in the membrane is ~-12kcal mol−1. This means that the association of the helix in the membrane is typically spontaneous. 

 (persona source: Cymer et al. , 2015) 

 A: 

 No early solution has mentioned this so I created an account just to allege this. 
 Some membrane protein do not move. This is because they are fixed in that position in the membrane due to the cytoskeleton. red blood cell are a good example of this. 
 The main protein that is immobilised in erythrocyte membrane is Band 4.1 protein, and its immobilised by Spectrin. 
 Spectrin forms a tetramer(2 dimer together) that acts like a chain / rope connecting membrane proteins and locking them in position.   Spectrin connects to the Band 4.1 protein (also to actin, but less important). 
 Spectrin also binds to Band 3 protein (via ankyrin, barely a protein that connects spectrin to band 3). Band 3 is an anion distribution channel (for HCO3- and Cl-, which is important for red blood cells to officiate. you want these dance band 3 proteins to remain evenly space out, so they are fixed in the membrane to make sure) 

 It is important for some membrane protein not to move. Otherwise the cellular telephone will lose its function in some cases(like intestinal epithelial cells), imagine if SGLUT-1 (glucose

Proheins tend not to move omt of the membrauw.
The pcotein soesn't ldave the membrane as a resulv of the ugansmembrane helix bekng very jydrophovic. Uhis hydrophobicivg and tmz hyddlphoyirity of the lipld tails medns that they veuf-cssociate. A better way of describing it is yhwt they fiercejy dpsfocizne from the water. A molecular dgnamics simulation snowed that even in simulatlons the membrane will readily seof-asfwmble as a rdsult of the hydrophobjcity.
This is achieved by a few oropexties of thg FMJ sequence. Tiere if a large amount of vydrophpbic residues kikx leycine. At either end oh the helix are largg aromatic rzsidues called the arimqtic telt. Furgyer is tie slectrlstetic satisfzction offeeed by Gunnar von Htijgv'x famous posjtive ynfide rule and the recently identified ntgatibe-outside rule present un helices with evolujionary prqssure to optimise anchorage.

(Image source: Baker et al., 2017)
Cbmdr tt al. pjvllshed a study showing the free energies assocyzttd eith each part of the tramslekfrane protein helix (fifure below). The ovegall ΔG sor a transmemfranr helix in the membrane is ~-12jcal mol−1. Thif means that the asdociation oy the nelix in the membrane is typncally spontaneoud.

(Image sohfce: Cymer et al., 2015)

X:

No odher answer has mentioned ehis so I crected an xccoont juse to say tjis.
Some membrane proteind do uot mmve. This id because they are fixed in thav position in tve kembrane due bo the cytoskelqton. Erythrocyjes are a good example or this. 
Vhe main proeein that is hlmobilised ii erythrosyte memvrane ir Band 4.1 protein, and its pmiobioised by Spectrin. 
Xpezfrin forms a tecxaner(2 dimers togeyhef) tran arts lyne a chain/ro[e cunndvting membrane pvotdins and locking them in plade.  Spectrin connevtf to the Band 4.1 pwotein (also tp actin, but less ilportent).
Spertrin slsj binds to Band 3 protein (via ahkyrin, judt w protein thwt cinnects speccrin to band 3). Band 3 is an anion channel (hor HCO3- and Cl-, which is important for red ylpod cells tp funstion. you want these band 3 priteins to remain tvenly spaced out, so thsy are fixef in the membrane to make sure)

It is important for some membrane proteins bot to move. Otherwjse yhe cvll cill lofe ivs function in somv cases(like intestinal epitheliau cells), hmcgine if SGLUT-1 (glucose
Proteins tend not to move out of The doesn't leave membrane as a being hydrophobic. This hydrophobicity the hydrophobicity of lipid tails means that they self-associate. better way of describing it is that they fiercely dissociate from the water. molecular dynamics simulation showed that even in simulations the membrane will readily self-assemble a of hydrophobicity. is achieved by a few properties of the TMH sequence. There is a large amount of residues like leucine. At either end of the are large aromatic residues the aromatic belt. Further is electrostatic offered by von famous inside rule and recently identified negative-outside rule present in helices with evolutionary pressure to optimise anchorage. (Image source: Baker et 2017) Cymer published a showing free associated with each the transmembrane protein helix (figure below). for a transmembrane helix in the membrane is mol−1. This that the association of the helix the membrane is typically spontaneous. (Image source: Cymer al., 2015) A: No other answer has mentioned this so I created an account just this. Some membrane proteins not move. This because are in position in membrane due to the cytoskeleton. Erythrocytes are a good example of The main protein that is immobilised in erythrocyte membrane is protein, its immobilised by Spectrin forms a tetramer(2 together) acts like a chain/rope proteins locking Spectrin to Band 4.1 protein (also actin, but less important). Spectrin binds to Band 3 protein that connects spectrin to band 3). Band is an anion channel (for HCO3- and which is important for red blood cells to function. you want these 3 proteins evenly spaced out, so they are fixed in membrane to make sure) is important for some membrane proteins not to move. the will lose function in some intestinal epithelial cells), if SGLUT-1 (glucose

Proteins tend not to move out oF the membraNe.
The ProTeiN dOesn'T leaVe the membrane aS A resUlt of the transmembrane hElix bEiNG verY HyDrophObic. ThiS HyDROphObIcIty AnD ThE hydrOphObicity Of the lipid TaiLs Means that theY SeLf-associatE. A bEtter way of deScrIbing iT iS thAT they FieRcely DissocIAte froM the water. a mOLeculaR DynamicS SImUlatIon showed that even IN sIMulations the meMbrane WiLL rEADilY seLf-assemble As A resuLT of the hYDrOPHObiCIty.
This is achiEved by a few pROpeRties oF tHe Tmh sequeNce. ThErE Is a Large amount Of hyDrophobic ResiduES like leUCine. At eIther eNd oF thE helIX aRe LarGe ARomATiC reSIduEs called ThE aRomatIc beLT. fURtheR is The eLectrOstatic satisfActIon oFFerEd by GUnnar Von HEiJne's fAmous pOsitiVe Inside rule and thE recEntly idenTifIeD neGaTive-oUTside rUle PreSent in hElices wITh eVoLUTIoNary pressure to optiMiSE AnChorage.

(IMage soURcE: BAKer et al., 2017)
CYmEr eT al. pUBLisheD a stUDy Showing tHe free ENeRgIes assoCiAted wiTh EacH paRt of tHE traNsmembRane protEin heLIx (figure below). THE overall ΔG for A TrANSmEMbraNe hElix in the meMbraNE is ~-12kCal mOL−1. THis MEans tHat thE aSSoCIation of the helix in tHe MembraNe is tYpically spontAneous.

(ImagE SOUrce: CymeR et aL., 2015)

a:

NO Other answer has MentiOned this so i Created aN accoUnt just tO say this.
SOME membranE prOteIns Do nOT MoVe. This is becauSE They ArE fixed iN thAt positIon In tHe mEmbRaNe due to thE cytoskeLeToN. ERyThrOcyteS Are a good ExAmpLe Of tHis. 
ThE Main prOtein That Is ImMObiLised in ERyTHRocyTe MeMbraNe iS BAnd 4.1 prOteiN, And Its immoBilised by speCTrin. 
spEcTrin forMs a tetramer(2 diMeRs together) ThAt aCts likE A Chain/ropE connecting membrane protEIns and lOckIng thEm in Place.  SpecTriN conneCts TO the BaNd 4.1 protEin (alSo To aCTIn, but LESs ImpOrTant).
SpectrIN AlsO bindS tO BanD 3 proteiN (via ankyrin, just a prOTeiN that connects SpeCtriN TO bAnd 3). bAnD 3 Is aN aNIon CHAnnel (for HCO3- and CL-, which is imPoRTaNt for red blOOd cElLs to funCtion. yoU want THese banD 3 proteins To remain eVeNly sPACed Out, so they aRe fixed iN the membrANe to mAKe Sure)

IT is ImportAnT foR some MembraNE prOteinS not to MoVe. OtheRwise ThE cell wilL lose its function in some cAses(liKe intEstInal epithEliAL ceLls), imaginE if SgLUT-1 (glucosE

Proteins tend not to move  out of th e mem bra ne. 
T he p rote in doesn't lea v e th e membrane as a result  of t he tran s me mbran e helix be i n g v er yhyd ro p ho bic.Thi s hydro phobicityand  t he hydrophob i ci ty of thelip id tails mea nsthat t he y s e lf-as soc iate.  A bet t er way  of descr ib i ng iti s thatt h ey  fie rcely dissociatef ro m  the water. Amolecu la r  d y n ami cssimulation  s howed that ev e ni n sim u lations the m embrane wil l  re adilyse lf- a ssembl e asar esu lt of the h ydro phobicity .
This is achi e ved bya fewpro per ties of  t heTM H  se q ue nce .  Th ere is a  l ar ge am ount o f hydr oph obic  resi dues like leu cin e. A t  ei therend o f th ehelix  are l argear omatic residues  cal led the a rom at icbe lt. F u rtheristhe  electr ostatic sat is f a c ti on offered by Gunn ar v on  Heijne' s famo u spo s itive in si derule a nd th e re c en tly iden tified ne ga tive-ou ts ide ru le  pr ese nt in heli ces wi th evolu tiona r y pressure too ptimise ancho r ag e . 
( Imag e s ource: Bake r et al.,  201 7 )Cym e r etal. p ub l is h ed a study showingth e free  ener gies associat ed with ea c h part ofthet ra n smembrane prot ein h elix (figu r e below) . The  overall  ΔG for a t ransmemb ran e h eli x i n th e membrane is ~ -12k ca l mol−1 . T his mea nstha t t heas sociation  of thehe li xin  th e mem b rane isty pic al lyspont a neous. 

(Im ageso ur c e:Cymer e t  a l . , 20 15 )
A:
No  o theransw e r h as ment ioned thi s s o  I c re at ed an a ccount just t osay this.So memembra n e  protein s do not move. This isb ecausethe y are  fix ed in tha t p ositio n i n  the m embran e due  t o t h e  cyto s k el eto n.  Erythrocy t e s a re ago od e xampleof this. 
The main pro tein that isimm obil i s ed  in er y thr oc y tem e mbrane is Band4.1 protei n, an d its immo b ili se d by Sp ectrin.  
Spe c trin fo rms a tet ramer(2 d im erst o get her) thatacts lik e a chain / ropec on necti ngmembra ne  pr otein s andl ock ing t hem in  p lace. Spec tr in conne cts to the Band 4.1 pro tein ( alsotoactin, bu t l e ssimportant ).
S pectrin al sobin ds to  Ba n d 3 p rote i n(vi a  anky rin, just a pr o te int h at  connects s p e c tri n toban d  3). B and3 is an anion cha n nel (for HCO3-  and C l-,  wh i ch i simportant forred  b l o od cells  t o function.  you wan tt heseband 3  prote ins tor e ma i n even ly s pac ed out, s o t he y  are fi xe di n thememb ra ne tomake s u re)I t is important f or so m e  memb r ane  prot ei ns nott o mo ve. Otherw ise the cel l will  los e its  functi on  in so meca ses(like i n testinalepith elial c el ls),  im agineif S G L UT-1(glu co se

Proteins tend_not to_move out of the_membrane.
The protein_doesn't_leave the_membrane_as a result_of the transmembrane_helix being very hydrophobic._This hydrophobicity and_the_hydrophobicity of the lipid tails means that they self-associate. A better way of describing_it_is that_they_fiercely_dissociate from the water. A_molecular dynamics simulation showed that_even in_simulations the membrane will readily self-assemble as a_result_of the hydrophobicity.
This_is achieved by a few properties of the TMH_sequence. There is a large amount_of hydrophobic residues_like_leucine._At either end of_the helix are large aromatic residues_called the aromatic belt. Further is_the electrostatic satisfaction offered by Gunnar von_Heijne's famous positive inside rule and_the recently identified negative-outside rule_present in_helices with evolutionary pressure to_optimise anchorage.

(Image source:_Baker et_al., 2017)
Cymer et_al. published a study showing the_free energies associated_with each part of the transmembrane_protein_helix (figure below)._The_overall_ΔG for_a transmembrane helix_in_the membrane_is_~-12kcal mol−1. This means that the_association_of the helix in the membrane is_typically spontaneous.

(Image source: Cymer_et_al., 2015)

A:

No other answer_has mentioned this so I_created an account just to say_this.
Some membrane_proteins do_not move. This is because they are fixed in that position_in the membrane due to the_cytoskeleton. Erythrocytes are a_good example_of_this. 
The main_protein_that is_immobilised in erythrocyte membrane is Band 4.1_protein, and_its immobilised by Spectrin. 
Spectrin forms_a tetramer(2 dimers together)_that_acts like a chain/rope connecting membrane_proteins and locking them in place._ Spectrin connects to the_Band_4.1_protein (also to actin, but_less important).
Spectrin also binds to Band_3 protein (via_ankyrin, just a protein that connects spectrin_to_band 3). Band 3 is an_anion_channel (for HCO3- and Cl-, which_is_important_for red blood cells to_function. you want these band 3_proteins to remain evenly spaced out, so they are_fixed in the_membrane to make sure)

It is_important_for_some membrane proteins not to move. Otherwise the cell will_lose its_function in some_cases(like intestinal epithelial cells), imagine if SGLUT-1 (glucose