Descriptions

ACTN2 is a major F-actin cross-linking protein in both muscle and non-muscle cells and a major multivalent platform mediating interactions with many cytoskeletal or regulatory proteins. An interaction between the C-terminal region of ACTN2 and the Z-repeat motifs of Titin protein targets ACTN2 to the Z-disk. Full-length ACTN2 does not bind Z-repeats. ACTN2 has a region that acts as a pseudo-Z-repeat between the actin-binding domain (ABD) and the spectrin-like repeats (R1), and this region prevents ACTN2 from binding to the Z-repeat of Titin protein. This autoinhibition is relieved upon binding of the Z-disk lipid phosphatidylinositol-bisphosphate to the ABD of ACTN2.

Autoinhibitory domains (AIDs)

Target domain

772-924 (EF-hand domain)

Relief mechanism

Ligand binding

Assay

Accessory elements

No accessory elements

Autoinhibited structure

Activated structure

1 structures for P18091

Entry ID Method Resolution Chain Position Source
AF-P18091-F1 Predicted AlphaFoldDB

No variants for P18091

Variant ID(s) Position Change Description Diseaes Association Provenance
No variants for P18091

No associated diseases with P18091

3 regional properties for P18091

Type Name Position InterPro Accession
domain PDZ domain 656 - 743 IPR001478-1
domain PDZ domain 747 - 823 IPR001478-2
domain PTB/PI domain 456 - 643 IPR006020

Functions

Description
EC Number
Subcellular Localization
  • Cytoplasm, myofibril, sarcomere, Z line
  • Colocalizes with Smn at the Z-line of indirect flight muscles
PANTHER Family
PANTHER Subfamily
PANTHER Protein Class
PANTHER Pathway Category No pathway information available

6 GO annotations of cellular component

Name Definition
cell junction A cellular component that forms a specialized region of connection between two or more cells, or between a cell and the extracellular matrix, or between two membrane-bound components of a cell, such as flagella.
cell projection A prolongation or process extending from a cell, e.g. a flagellum or axon.
cortical actin cytoskeleton The portion of the actin cytoskeleton, comprising filamentous actin and associated proteins, that lies just beneath the plasma membrane.
focal adhesion A cell-substrate junction that anchors the cell to the extracellular matrix and that forms a point of termination of actin filaments. In insects focal adhesion has also been referred to as hemi-adherens junction (HAJ).
plasma membrane The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins.
Z disc Platelike region of a muscle sarcomere to which the plus ends of actin filaments are attached.

3 GO annotations of molecular function

Name Definition
actin binding Binding to monomeric or multimeric forms of actin, including actin filaments.
actin filament binding Binding to an actin filament, also known as F-actin, a helical filamentous polymer of globular G-actin subunits.
calcium ion binding Binding to a calcium ion (Ca2+).

4 GO annotations of biological process

Name Definition
actin cytoskeleton organization A process that is carried out at the cellular level which results in the assembly, arrangement of constituent parts, or disassembly of cytoskeletal structures comprising actin filaments and their associated proteins.
actin filament bundle assembly The assembly of actin filament bundles; actin filaments are on the same axis but may be oriented with the same or opposite polarities and may be packed with different levels of tightness.
muscle cell development The process whose specific outcome is the progression of a muscle cell over time, from its formation to the mature structure. Muscle cell development does not include the steps involved in committing an unspecified cell to the muscle cell fate.
sarcomere organization The myofibril assembly process that results in the organization of muscle actomyosin into sarcomeres. The sarcomere is the repeating unit of a myofibril in a muscle cell, composed of an array of overlapping thick and thin filaments between two adjacent Z discs.

17 homologous proteins in AiPD

UniProt AC Gene Name Protein Name Species Evidence Code
A5D7D1 ACTN4 Alpha-actinin-4 Bos taurus (Bovine) SS
Q0III9 ACTN3 Alpha-actinin-3 Bos taurus (Bovine) SS
Q3B7N2 ACTN1 Alpha-actinin-1 Bos taurus (Bovine) SS
Q3ZC55 ACTN2 Alpha-actinin-2 Bos taurus (Bovine) SS
P20111 ACTN2 Alpha-actinin-2 Gallus gallus (Chicken) SS
Q90734 ACTN4 Alpha-actinin-4 Gallus gallus (Chicken) SS
P05094 ACTN1 Alpha-actinin-1 Gallus gallus (Chicken) SS
O43707 ACTN4 Alpha-actinin-4 Homo sapiens (Human) SS
P12814 ACTN1 Alpha-actinin-1 Homo sapiens (Human) SS
P35609 ACTN2 Alpha-actinin-2 Homo sapiens (Human) EV
Q08043 ACTN3 Alpha-actinin-3 Homo sapiens (Human) SS
O88990 Actn3 Alpha-actinin-3 Mus musculus (Mouse) SS
P57780 Actn4 Alpha-actinin-4 Mus musculus (Mouse) SS
Q7TPR4 Actn1 Alpha-actinin-1 Mus musculus (Mouse) SS
Q9JI91 Actn2 Alpha-actinin-2 Mus musculus (Mouse) SS
Q9QXQ0 Actn4 Alpha-actinin-4 Rattus norvegicus (Rat) SS
Q9Z1P2 Actn1 Alpha-actinin-1 Rattus norvegicus (Rat) SS
10 20 30 40 50 60
MMMENGLSME YGDGYMEQEE EWEREGLLDP AWEKQQKKTF TAWCNSHLRK AGTAIDNIEE
70 80 90 100 110 120
DFRNGLKLML LLEVISGETL PKPDRGKMRF HKIANVNKAL DFIASKGVHL VSIGAEEIVD
130 140 150 160 170 180
GNLKMTLGMI WTIILRFAIQ DISVEEMTAK EGLLLWCQRK TAPYKNVNVQ NFHLSFKDGL
190 200 210 220 230 240
AFCALIHRHR PDLIDYAKLS KDNPLENLNT AFDVAEKYLD IPRMLDPDDL INTPKPDERA
250 260 270 280 290 300
IMTYVSCYYH AFQGAQQVGN NTALPDERAV MTYVSSYYHC FSGAQKAETA ANRICKVLKV
310 320 330 340 350 360
NQENERLMEE YERLASDLLE WIRRTMPWLN SRQADNSLAG VQKKLEEYRT YRRKHKPPRV
370 380 390 400 410 420
EQKAKLETNF NTLQTKLRLS NRPAYLPTEG KTVSDISNSW KGLELAEKAF EEWLLAETMR
430 440 450 460 470 480
LERLEHLAQK FKHKADAHED WTRGKEEMLQ SQDFRQCKLN ELKALKKKHE AFESDLAAHQ
490 500 510 520 530 540
DRVEQIAAIA QELNTLEYHD CVSVNARCQR ICDQWDRLGA LTQRRRTALD EAERILEKID
550 560 570 580 590 600
ILHLEFAKRA APFNNWLDGT REDLVDMFIV HTMEEIQGLI QAHDQFKATL GEADKEFNLI
610 620 630 640 650 660
VNLVREVESI VKQHQIPGGL ENPYTTLTAN DMTRKWSDVR QLVPQRDQTL ANELRKQQNN
670 680 690 700 710 720
EMLRRQFAEK ANIVGPWIER QMDAVTAIGM GLQGSLEDQL HRLKEYEQAV YAYKPNIEEL
730 740 750 760 770 780
EKIHQAVQES MIFENRYTNY TMETLRVGWE QLLTSINRNI NEVENQILTR DSKGISQEQL
790 800 810 820 830 840
NEFRSSFNHF DKNRTGRLSP EEFKSCLVSL GYSIGKDRQG DLDFQRILAV VDPNNTGYVH
850 860 870 880 890 900
FDAFLDFMTR ESTDTDTAEQ VIDSFRILAA DKPYILPDEL RRELPPDQAE YCIQRMPPYK
910 920
GPNGVPGALD YMSFSTALYG ETDL